Barney having back-up playbooks is completely in character, if you ask me. I was not at all surprised he'd have one. He's Barney - he thinks 10 steps ahead all the time. Having a back-up is only one step ahead! Besides, I thought he'd end up bequeathing the playbook to Ted, or maybe even to Marvin. It was his life's work; for it to end up as confetti was anticlimactic.